<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <style>
        .bw{
            width: 500px;
            height: 250px;
            background-color: green;
            background-image: url(1.png);
            background-repeat: no-repeat;
             /* 设置背景图片的位置 */
             /* background-position: right top; */
             /* background-position: left bottom; */
             /* 如果只指定了一个值，另外一个值默认就是居中对齐 */
             /* background-position: top; */
             /* background-position: 20px 20px; */
             /* background-position: 20px center; */
             background-position: center 20px;
        }
    </style>
</head>
<body>
    <div class="bw" >
       
    </div>
</body>
</html>